1. Field of the Invention:
The present invention relates to biopolymer-based compositions, and, more especially, to stable oil-in-water emulsions having high concentrations in biopolymers, and to processes for the preparation and use thereof.
2. Description of the Prior Art
Biopolymers or biogums are defined as heteropolysaccharides of microbial origin obtained by the fermentation of a carbohydrate assimilable by appropriate microorganism. The most representative example of such biopolymers is xanthan gum. By virtue of their thickening properties and their rheology, heteropolysaccharides have found various applications, in particular in the field of foods and in the construction, paint, paper, textile, cosmetic, and phytosanitary industries, in the treatment of waters and the petroleum industry, for example, in drilling and the assisted recovery of oil.
For numerous applications it is necessary to constitute the biopolymer in the form of a low concentration aqueous solution. It is known that the major disadvantage of biogum powders is the difficulty in dissolving them rapidly without agitation with a high shear effect, which could cause a degradation of certain properties. For applications which do not require a high purity polymer, it would be possible to use the fermentation wort directly, but the cost of transporation is an obstacle to the commercial development of such products.
In order to increase the dispersibility of xanthan gum and to facilitate its use, highly concentrated polymer compositions have already been proposed. Thus, European Patent No. 016,640 describes "slurries" of xanthan gum in a hydrophobic solvent containing a suspension agent. These suspensions are prepared from polymer powders.